The present teachings are predicated upon providing a large continuous tissue sample during a biopsy so that an accurate assessment can be made. Current systems include a needle that extends into tissue and vacuum is applied to assist in retaining the sample within the needle. An adequate or reliable sample may not be removed on the first attempt and, thus, the needle may have to be extended into a tissue sample multiple times before a sufficient sample is removed. Repeatedly extending the needle into a location may result in increased trauma to an area, multiple small samples being taken, or both. Additionally, an application of suction during sampling may cause fluids to be drawn into the needle with the sample, may cause small particles of sample to be drawn into the needle, or both. If too much fluid, such as blood, is drawn into the needle during sampling, the sample may be compromised and may not be usable, and if the samples are too small the samples may not be usable.
Current needles used to perform a biopsy are limited in size by the size of the endoscope or bronchoscope used in a procedure or the size of the sheath that extends from one or more of the channels of the endoscope or bronchoscope. As the size of the channels in the endoscope or bronchoscope become smaller the sizes of the needles being used become smaller, which limits the size of the sample that can be taken. Examples of biopsy devices may be found in U.S. Pat. No. 8,911,467; and International Patent Application Publication No. WO2015/004571; all of which are incorporated by reference herein in their entirety for all purposes.
It would be attractive to have a needle that is expandable to take a sample that is larger than the size (e.g., diameter) of the needle while the needle is located within the sheath and/or delivery device. What is needed is a device to assist in retaining the sample within the needle once a sample is taken without the application of vacuum or with a reduced application of suction. It would be attractive to have a device that resists the sample from being pulled from the needle when the needle is retracted. What is needed is a device that assists in cutting an attached portion of a sample or prevents removal of a sample due to an attached portion. It would be attractive to have a device that rotationally cuts a sample while the needle is extended axially into a sample site.